File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

DBF file extension

Database File

Database Files

DEB file extension

Debian Software Package

Compressed Files

GBR file extension

Gerber File

Data Files

IBOOKS file extension

Multi-Touch iBook

Data Files

JAR file extension

Java Archive File

Executable Files

JPG file extension

JPEG Image

Raster Image Files

KMZ file extension

Google Earth Placemark File

GIS Files

MDF file extension

Media Disc Image File

Disk Image Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

PS file extension

PostScript File

Vector Image Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

RM file extension

Real Media File

Video Files

TEX file extension

LaTeX Source Document

Text Files

XHTML file extension

Extensible Hypertext Markup Language File

Web Files

XML file extension

XML File

Data Files